Hardened fiber optic connector

ABSTRACT

The present disclosure relates to a fiber optic connector for use with a fiber optic adapter. The fiber optic connector includes a connector housing having an end defining a plug portion. A ferrule assembly is mounted at least partially within the connector housing. The ferrule assembly includes a ferrule located at the plug portion of the connector housing. A sealing member is mounted about an exterior of the connector housing for providing a seal between the connector housing and the adapter. The fiber optic connector further includes first and second separate retaining mechanism for retaining the fiber optic connector within the fiber optic adapter.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/323,135, filed on Jul. 3, 2014, now U.S. Pat. No. 9,664,862, issuedon May 30, 2017, titled HARDENED FIBER OPTIC CONNECTOR, which is acontinuation of U.S. application Ser. No. 12/333,509, filed on Dec. 12,2008, now U.S. Pat. No. 8,770,862, issued on Jul. 8, 2014, titled“HARDENED FIBER OPTIC CONNECTOR,” which is a continuation of U.S.application Ser. No. 11/657,402, filed on Jan. 24, 2007, now U.S. Pat.No. 7,572,065, issued on Aug. 11, 2009, titled “HARDENED FIBER OPTICCONNECTOR,” the disclosures of which are hereby incorporated byreference in their entireties.

TECHNICAL FIELD

The present disclosure relates to fiber optic data transmission, andmore particularly to fiber optic cable connection systems.

BACKGROUND

Fiber optic cables are widely used to transmit light signals for highspeed data transmission. A fiber optic cable typically includes: (1) anoptical fiber or optical fibers; (2) a buffer or buffers that surroundsthe fiber or fibers; (3) a strength layer that surrounds the buffer orbuffers; and (4) an outer jacket. Optical fibers function to carryoptical signals. A typical optical fiber includes an inner coresurrounded by a cladding that is covered by a coating. Buffers (e.g.,loose or tight buffer tubes) typically function to surround and protectcoated optical fibers. Strength layers add mechanical strength to fiberoptic cables to protect the internal optical fibers against stressesapplied to the cables during installation and thereafter. Examplestrength layers include aramid yarn, steel and epoxy reinforced glassroving. Outer jackets provide protection against damage caused bycrushing, abrasions, and other physical damage. Outer jackets alsoprovide protection against chemical damage (e.g., ozone, alkali, acids).

Fiber optic cable connection systems are used to facilitate connectingand disconnecting fiber optic cables in the field without requiring asplice. A typical fiber optic cable connection system forinterconnecting two fiber optic cables includes fiber optic connectorsmounted at the ends of the fiber optic cables, and an adapter formechanically and optically coupling the fiber optic connectors together.Fiber optic connectors generally include ferrules that support the endsof the optical fibers of the fiber optic cables. The end faces of theferrules are typically polished and are often angled. The adapterincludes co-axially aligned ports (i.e., receptacles) for receiving thefiber optic connectors desired to be interconnected. The adapterincludes an internal sleeve that receives and aligns the ferrules of thefiber optic connectors when the connectors are inserted within the portsof the adapter. With the ferrules and their associated fibers alignedwithin the sleeve of the adapter, a fiber optic signal can pass from onefiber to the next. The adapter also typically has a mechanical fasteningarrangement (e.g., a snap-fit arrangement) for mechanically retainingthe fiber optic connectors within the adapter. One example of anexisting fiber optic connection system is described in U.S. Pat. Nos.6,579,014, 6,648,520, and 6,899,467.

SUMMARY OF THE DISCLOSURE

One aspect of the present disclosure relates to a fiber optic connectorhaving a dual fastening arrangement for securing the fiber opticconnector in a fiber optic adapter.

Another aspect of the present disclosure relates to a fiber opticconnector that is adapted to provide relatively high fiber optic circuitdensities at an enclosure.

A further aspect of the present disclosure relates to a fiber opticconnector having a tapered interface adapted to complement acorresponding tapered interface of a fiber optic adapter.

A variety of additional inventive aspects will be set forth in thedescription that follows. The inventive aspects can relate to individualfeatures and to combinations of features. It is to be understood thatboth the forgoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the broad inventive concepts upon which the embodiments disclosedherein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example fiber optic connection systemhaving features that are examples of inventive aspects in accordancewith the principles of the present disclosure;

FIG. 2 is a perspective view of the fiber optic connection system ofFIG. 1 with a connector of the fiber optic connection system terminatingthe end of a fiber optic cable;

FIG. 3 shows the fiber optic connection system of FIG. 1 with an adapterof the fiber optic connection system shown in phantom lines;

FIG. 4 shows the fiber optic connection system of FIG. 1 with an adapterof the fiber optic connection system mounted to a schematic enclosure;

FIG. 5 is an exploded, perspective view of the fiber optic connectionsystem of FIG. 1;

FIG. 6 is a cross-sectional view taken along section line 6-6 of FIG. 5;

FIG. 7 is an exploded, perspective view of the fiber optic connector ofthe fiber optic connection system of FIG. 1;

FIG. 8 is a perspective view of a main body of the housing of the fiberoptic connector of FIG. 7;

FIG. 9 is a plan view of the main body of FIG. 8;

FIG. 10 is a perspective view of a cover of the housing of the fiberoptic connector of FIG. 7;

FIG. 11 is a plan view of the cover of FIG. 10;

FIG. 12 is an exploded, perspective view of a fiber optic adapter of thefiber optic connection system of FIG. 1;

FIG. 13 is a view taken along section line 13-13 of FIG. 12;

FIG. 14 is an enlarged view of a portion of FIG. 3;

FIG. 15 is an enlarged view of a latch provided on the fiber opticconnector of the fiber optic connection system of FIG. 1;

FIG. 16 is a side view of the fiber optic connection system and fiberoptic cable of FIG. 2;

FIG. 17 is a cross-sectional view taken along section line 17-17 of FIG.16;

FIG. 18 is a top view of the fiber optic connection system and fiberoptic cable of FIG. 2;

FIG. 19 is a cross-sectional view taken along section line 19-19 of FIG.18;

FIG. 20 is a perspective view of another fiber optic connection systemhaving features that are examples of inventive aspects in accordancewith the principles of the present disclosure;

FIG. 21 is a top view of the fiber optic connection system of FIG. 20;

FIG. 22 is a cross-sectional view taken along section line 22-22 of FIG.23; and

FIG. 23 is an end view of the fiber optic connection system of FIG. 20.

DETAILED DESCRIPTION

FIGS. 1-5 depict a fiber optic connection system 30 in accordance withthe principles of the present disclosure for optically connecting afirst fiber optic cable 20 (see FIG. 4) to a second fiber optic cable 22(see FIG. 4). The fiber optic connection system 30 includes a fiberoptic adapter 34, a first fiber optic connector 32 terminating the firstcable 20, and a second fiber optic connector 33 (shown at FIG. 3)terminating the second fiber optic cable 22. The adapter 34 is depictedmounted to an enclosure 19 (shown schematically at FIG. 4). The adapter34 includes a first port 35 for receiving the first connector 32 and asecond port 37 for receiving the second connector 33. The first cable 20is optically coupled to the second cable 22 when the connectors 32, 33are positioned within their respective ports 35, 37 of the adapter 34.

As shown at FIG. 4, the first cable 20 is an external cable (e.g., anoutside plant cable located outside the enclosure 19) and the secondcable 22 is located inside the enclosure 19. In such an embodiment, thefirst cable 20 cable is adapted to carry an optical signal to theenclosure 19 and the fiber optic connection system 30 allows the signalto be transferred from the first cable 20 to the second cable 22.

The cables 20 and 22 each include one or more optical fibers capable ofcarrying optical signals. The optical fibers include a core surroundedby cladding. The core is the light-conducting central portion of anoptical fiber. The cladding surrounds the core and is composed of amaterial having a lower index of refraction than the material of thecore. Light is internally reflected within the core to transmit theoptical signal along the core. The optical fibers can be protectedwithin buffer tubes. The fiber optic cables also can include strengthmembers within the fiber optic cables to increase the tensile strengthof the fiber optic cables. The optical fibers, strength members, buffertubes and other cable components can be surrounded by an outer jacket orsheath that provides a protective covering for cable components. Asshown at FIG. 5, the first cable 20 includes a central buffer tube 220containing at least one optical fiber 222. Strength members 224 arepositioned on opposite sides of the central buffer tube 220. Thestrength members 224 and the buffer tube are positioned within an outerjacket 226 of the cable 20.

The enclosure 19 can include a wide variety of opticalenclosures/housings (e.g., drop terminals, pedestals, network interfacedevices, fiber distribution hubs, splice enclosures, optical networkterminals, etc.). In one embodiment, adapters 34 can be mounted to adrop terminal of the type disclosed at U.S. patent application Ser. No.11/075,847, entitled Fiber Access Terminal, filed on Mar. 8, 2005, andthat is hereby incorporated by reference in its entirety. For suchembodiments, the cable 20 can be a drop cable routed to a subscriberpremises and the cable 22 can be a connectorized fiber from a stub cablethat is routed from the drop terminal to a fiber break-out location of afiber distribution cable. Example fiber break-out configurations aredisclosed at U.S. patent application Ser. No. 11/491,336, entitled FiberOptic Cable Breakout Configuration with Retention Block, filed on Jul.21, 2006, and that is hereby incorporated by reference in its entirety.In another embodiment, one or more of the adapters can be mounted to anetwork interface device of the type disclosed at U.S. application Ser.No. 11/607,676, entitled Network Interface Device, filed on Dec. 1,2006, and that is hereby incorporated by reference in its entirety. Insuch an embodiment, the first cable 20 can include a drop cable and thecable 22 can include a connectorized cable/fiber positioned within thenetwork interface device. Alternatively, fiber optic connection system30 can also be used without an enclosure (e.g., the adapter can be panelmounted).

In the depicted embodiment, the first connector 32 and the adapter 34are hardened or ruggedized. By hardened or ruggedized, it is meant thatfirst connector 32 and the adapter 34 are adapted for outsideenvironmental use. For example, the first connector 32 and the adapter34 can include environmental seals for preventing moisture/waterintrusion. Also, it is preferred for the first connector 32 to be ableto withstand a 100 pound axial pull-out force when coupled to theadapter 34. The second connector 33 can be a conventional fiber opticconnector such as a Subscription Channel (“SC”) connector. One exampleof an SC connector is illustrated and described in U.S. Pat. No.5,317,663, that is hereby incorporated by reference in its entirety.

Referring to FIGS. 5 and 7, the first connector 32 includes a connectorhousing 39 including a main body 36 and a cover 41. The connectorhousing 39 extends from a distal end 52 to a proximal end 54 (distal andproximal are defined with respect to the connection with fiber opticcable 20 for connector 32). A ferrule assembly 43 mounts adjacent thedistal end 52 of the connector housing 39 and a strain relief boot 42mounts adjacent the proximal end 54 of the connector housing 39. Asealing member 49 (e.g., an o-ring seal) mounts around aperiphery/exterior of the connector housing 39. The sealing member 49 isadapted for providing a seal between the connector housing 39 and theadapter 34 when the first connector 32 is plugged into the first port 35of the adapter 34. The first connector 32 also includes a crimp band 38that mounts over the main body 36 and the cover 41, and a sealing tube106 that seals the interface between the cable 20 and the connectorhousing 39. The crimp band 38 assists in retaining the cover 41 on themain body 36 and also assists in securing the strength members 224 ofthe cable 20 in place between the cover 41 and the main body 36. Thefirst connector 32 also includes first and second fastening structuresfor retaining (i.e., connecting, securing, etc.) the first connector 32within the first port 35 of the adapter 34. For example, the firstconnector 32 can include a latch 50 (see FIGS. 3, 7, 14 and 15) formechanically interlocking with the adapter 34 when the first connector32 is inserted in the first port 35. The first connector 32 alsoincludes a coupling nut 40 adapted to thread into the adapter 34 toretain the first connector 32 within the first port 35 of the adapter34.

The connector housing 39 of the connector 32 extends from distal end 52to proximal end 54. A plug portion 56 is defined at the distal end 52and two tabs 58 are provided at the proximal end 54. One of the tabs 58is provided by the body 36 of the housing and the other of the tabs 58is provided by the cover 41 of the housing 39. The body 36 is depictedas a unitary molded piece (e.g., a molded plastic piece as shown atFIGS. 7-9) and the cover 41 is depicted as a separate unitary moldedpiece (e.g., a molded plastic piece as shown at FIGS. 7, 10 and 11). Acentral passage 118 is defined through the interior of the connectorhousing 39 from the proximal end 54 to the distal end 52. The centralpassage 118 has a distal portion 118 a defined through the plug portion56 of the connector housing 39 and a proximal portion 118 b definedbetween the body 36 and the cover 41. The proximal portion 118 b of thecentral passage 118 is defined in part by the body 36 and in part by thecover 41. Removal of the cover 41 from the body 36 provides lateralaccess to the proximal portion 118 b of the central passage 118. Thedistal portion 118 a of the passage 118 is defined entirely by the body36 and extends through the plug portion 56. The distal portion 118 a ofthe passage 118 has a distal end at the distal end 52 of the housing 39and a proximal end adjacent the proximal portion 118 b of the passage118.

The plug portion 56 of the first connector 32 is sized and shaped to fitwithin the first port 35 of the adapter 34, as shown at FIGS. 3, 17 and19. The distal end of the plug portion 56 preferably has a taperedconfiguration that mates or matches (e.g., nests, complements) with atapered portion of a first plug receptacle 59 accessed from the firstport 35 (see FIG. 17). As shown at FIG. 17, the tapered configuration isdefined by opposite surfaces (e.g., left and right surfaces 61, 63) thatconverge as the surfaces extend along a central axis A1 of the connector32 in a distal direction. The end of the plug portion 56 is truncated.When the plug portion 56 is positioned within the first plug receptacle59, the surfaces 61, 63 engage and are parallel to or generally parallelto angled surfaces 67, 69 that define the first plug receptacle 59.

As shown at FIGS. 14 and 15, the latch 50 of the first connector 32 isprovided at a top side of the plug portion 56. The latch 50 has acantilever arm 90 with a base end 81 that is integrally molded with theplug portion 56. The arm 90 extends in a distal direction from the baseend 81 to a free end 83. A retention tab 51 is provided adjacent thefree end 83 of the arm 90. The retention tab 51 includes an inclinedregion 92 and a declined region 94. The arm 90 is configured to flex asthe plug portion 56 is inserted into the first port 35 of the adapter34, and to provide a snap-fit connection between the first connector 32and the adapter 34 when the plug portion 56 is fully inserted into thefirst port 35. For example, as shown at FIG. 14, retention tab 51 snapswithin a latch notch 82 defined by the adapter 34 when the plug portion56 is fully inserted in the first port 35. The latch notch 82 is definedin part by a retention surface 96.

When inserting the plug portion 56 into the first port 35 of the adapter34, the arm 90 of the latch 50 is flexed toward axis A1 by adapter 34 asthe inclined region 92 comes into contact with adapter 34. Arm 90 isdesigned of a material capable of flexing when compressed, such as aplastic. Insertion of plug portion 56 into the port 35 continues untilthe inclined region 92 passes by the retention surface 96 of the notch82. After the inclined region 92 is entirely past the retention surface96, the declined region 94 comes into contact with surface 96. A forcegenerated by the flexing of arm 90 causes the retention tab 51 to raiseas the declined region 94 proceeds past surface 96. Insertion continuesuntil declined region 94 is completely, or almost completely, past theretention surface 96 of the notch 82. At this point, compression of thearm 90 by adapter 34 is released, such that the arm 90 returns to itsuncompressed state. Alternatively, the adapter 34 can be designed toretain some of the compression of arm 90, if desired.

One of the benefits of the latch mechanism is that it provides a forcethat inhibits removal of the first connector 32 from the first port 35,such as to resist unintentional disengagement of the first connector 32from the first port 35. For example, if the first connector 32 begins tomove in a direction away from the first port 35, the declined region 94comes into contact with the retention surface 96 of latch notch 82. Atthis point, in order for the first connector 32 to be removed from thefirst port 35, a force must be applied in a direction away from thefirst port 35 sufficient to cause the arm 90 to compress as declinedregion 94 is pulled back along surface 96. The force required can beconfigured to be greater or lesser by adjusting the strength of the arm90, and also by adjusting the slope of declined region 94. The snap-fitconfiguration of the latch 50 also provides a physical and audibleindication that the first connector 32 has been fully inserted into thefirst port 35.

The inclined region 92 of the retention tab 51 has an angle of inclineillustrated as A2 and the declined region 94 of the retention tab 51 hasan angle of decline illustrated as A3. In the illustrated embodiment,angle A2 is less than angle A3. The benefit of this is that the latch 50will be easier to insert than it will be to remove, because thedecreased angle of incline (A2) will not present as much resistance toinsertion as the increased angle of decline (A3) will present toremoval. In one example, angle A3 is about double angle A2. In anotherexample, angle A2 is about equal to angle A3. It is recognized, however,than any angles may be formed for angles A2 and A3. In one example,angles A2 and A3 are in a range from about 0 degrees to about 90degrees, and preferably from 15 degrees to about 85 degrees. In anotherexample, angle A2 is in a range from about 15 degrees to about 45degrees and angle A3 is in a range from about 30 degrees to about 90degrees.

The inclined and declined regions 92 and 94 meet at a peak, having aheight H1. The arm 90 extends a height H2 above an adjacent portion ofplug portion 56. In one example, height H1 is about equal to height H2.Alternatively, height H2 is larger than height H1 to ensure that latch50 is not inhibited from movement by the adjacent portion of plugportion 56. Alternatively, height H2 can be less than height H1, so longas adequate space is provided to enable latch 50 to be appropriatelyinserted into notch 82.

In another example, angle A3 can be about 90 degrees, such that thedeclined region 94 extends generally perpendicular to the arm 90. Inthis example, the declined region 94 will not permit the latch 50 to beremoved by the mere application of a force in a direction away from theport 35. Rather, the latch 50 can be manually released, such as bymanually depressing the latch 50, such as through the notch 82. Thelatch 50 can be depressed, for example, by inserting a narrow releasetool through the notch 82 to depress the latch 50. Alternatively, abutton can be formed over the notch 82. The button can include an armthat extends through the notch 82, such that when the button isdepressed, the arm depresses the latch 50, enabling the first connector32 to be removed from the first port 35.

The coupling nut 40 of the first connector 32 is adapted to provide asecond connection mechanism for securing the first connector 32 to theadapter 34. After the latch 50 has interlocked with the adapter 34, thecoupling nut 40 can be threaded into corresponding threads providedwithin the first port 35 so as to provide a second connection with theadapter 34. The coupling nut 40 provides a connection with the adapter34 that has a substantially greater pull-out resistance from thepull-out resistance provided by the latch 50. In one example embodiment,the coupling nut 40 retains the first connector 32 in the first port 35even if a pull-out force of at least 100 pounds is applied to the firstconnector 32.

The coupling nut 40 of the first connector 32 includes a first region180 and a second region 182. The first region 180 includes a pluralityof grooves 184 to facilitate grasping of the first region 180, such asby a field technician or other user during connection or disconnectionof the connector 32 with the adapter 34. The grooves 184 are for examplea plurality of longitudinally oriented grooves that enable a user tomore easily rotate the coupling nut 40. Turning of the coupling nut 40enables a connection means of the second region 182 to engage ordisengage with the adapter 34. In the illustrated embodiment, the secondregion 182 includes a connection means of exterior screw threads 75adapted to mate with internal threads 76 provided within the first port35 of the adapter 34. In another embodiment, other connection means mayalso be used.

The ferrule assembly 43 of the first connector 32 includes a ferrule 100(e.g., a ceramic ferrule), a barrel 101 mounted on the ferrule 100, aspring 102 and a spring holder 104. The ferrule assembly 43 is loadedinto the first connector 32 while the cover 41 is removed from the mainbody 36. To load the ferrule assembly 43 into the connector housing 39,the ferrule 100 is positioned in the distal portion 118 a of the centralpassage 118 by inserting the ferrule 100 through the proximal end of thedistal portion 118 a. As so inserted, the barrel 101 abuts against ashoulder 103 located within the plug portion 56 (see FIGS. 17 and 19).The spring 102 is then inserted into the distal portion 118 a behind theferrule 100. Thereafter, the spring holder 104 is loaded into a pocket114 (see FIGS. 8-11) of the main body 36 at a location behind the spring102 such that the spring 102 is captured within the distal portion 118 abetween the barrel 101 and the spring holder 104. In this manner, theferrule 100 is spring biased in a distal direction.

The proximal portion of the connector housing 39 is configured tofacilitate providing a secure connection between the first cable 20 andthe first connector 32. For example, the proximal portion 118 b of thecentral passage 118 is sized to receive the buffer tube 220 of the firstcable 20. Strength member receivers 120 (e.g., channels, passages,grooves, etc.) are provided on opposite sides of the proximal portion118 b of the central passage 118 for receiving the strength members 224of the first cable 20. The body 36 includes alignment openings 116 thatreceive corresponding alignment pins 117 of the cover 41 to insure thatthat cover 41 properly aligns with the body 36 when mounted thereto. Theconnector housing 39 further includes bleed openings 122 for allowingadhesive to bleed from the interior of the housing 39 when the cover 41is mounted to the body 36. The interior of the housing 39 furtherincludes structure for improving adhesion between adhesive and theinterior of the housing. For example, the interior of the housingincludes a plurality of slots 123 for improving the adhesioncharacteristics of the interior surface of the housing 39. Otheradhesion improving structures include knurling, surface roughening, orother structures.

The exterior of the connector housing 39 includes a circumferentialgroove 112 for mounting the sealing member 49. The exterior of thehousing 39 also includes circumferential shoulders 124 and 125 (see FIG.7), against which the crimp band 38 can abut after assembly of theconnector, and a circumferential shoulder 113 (shown in FIGS. 8 and 9).A circumferential recessed portion 128 is defined on the outside of thetabs 58. Retaining teeth 130 are located on the inside of the tabs 58.

Installation of connector 32 onto the end of a fiber optic cable 20 willnow be described with reference to FIG. 5. To begin installation, theend of the fiber optic cable 20 is prepared using a stripping process.In the stripping process, the outer jacket 226 is stripped away toexpose the strength members 224 and the buffer tube 220. After thestripping process, a portion of the buffer tube 220 is cut away toexpose the optical fiber 222.

After the end of the cable 20 has been prepared as described above, theboot 42 is slid onto the end of fiber optic cable 20, followed by thesealing tube 106 (e.g., a heat shrink tube or heat shrink tape/wrap),the coupling nut 40, and the crimp band 38. The bare optical fiber 222is then fed through the spring holder 104 and the spring 102, and ismounted within the ferrule 100. The ferrule assembly 43 is then loadedinto the plug portion 56 of the connector housing 39.

Once the ferrule assembly has been loaded into the connector housing 39,the first cable 20 is secured to the connector housing 39 such thatcable 20 extends longitudinally from the proximal end 54 of the housing39. FIGS. 5 and 7 are perspective views of the body 36 having the cover41 separated from it, such as in position for installation with a fiberoptic cable. To make the connection, the strength members 224 of thefiber optic cable 20 are inserted into strength member receivers 120 andthe buffer tube 220 is inserted into the proximal portion 118 b of thecentral passage 118, such that the optical fiber 222 extends generallyalong axis A1. Adhesive is then applied to the buffer tube 220, strengthmembers 224, central passage 118, and strength member receivers 120,including those in both body 36 and cover 41. The adhesive may be anepoxy or any other type of adhesive. Alternatively, fasteners could alsobe used to connect cover 41 with body 36. The body 36 and the cover 41are properly aligned by the pins 117 located on the internal side ofcover 41 that are inserted into the alignment openings 116 of the body36. The cover 41 is then squeezed against body 36 to enclose thestrength members 224, the buffer tube 220 and the optical fiber 222within the connector housing 39. The adhesive bleed openings 122provided in the body 36 and the cover 41 enable excess adhesive to bedischarged from the housing 39. When the cover 41 is squeezed onto thebody 36, the excess adhesive flows out from bleed openings 122 and canthen be wiped away.

The fiber optic cable 20 is preferably stripped in the previous stepssuch that the outer jacket 226 terminates at a shoulder 136 (see FIGS.8-11) of the housing 39. The shoulder 136 is located at the distal endsof tabs 58 and at the proximate ends of strength member receivers 120and the central passage 118. The tabs 58, therefore, cover the end ofthe outer jacket 226 when the cover 41 and the body 36 are connected.When the cover 41 and the body 36 are pressed together, the teeth 130 ofthe tabs 58 are pressed into or against the outer jacket 226. The teeth130 are oriented to resist movement of the outer jacket 226 in theproximal direction away from the body 36. Therefore, the teeth 130provide further connection means to hold the fiber optic cable 20 firmlyengaged with the connector housing 39.

After the cover 41 has been connected with the body 36 and fiber opticcable 20, the crimp band 38 is slid over a part of the connector housing39 and crimped in place to hold the cover 41 securely onto the body 36.The sealing tube 106 is then slid over a portion of the crimp band 38 soas to cover the end of the cable 20, the proximal end of the connectorhousing 39 and at least a portion of the crimp band 38. Heat is thenapplied to the sealing tube 106 to cause the sealing tube 106 to shrinkand tightly form around the adjacent portions of the connector housing39, the crimp band 38, and the fiber optic cable 20, to seal connectorfrom foreign substances. The coupling nut 40 is then slid over the crimpband 38, the sealing tube 106 and the connector housing 39. The boot 42is then slid onto the first connector 32 and over the sealing tube 106.The boot 42 is, for example, a flexible polymeric/rubber material. Atthe distal end of the boot 42, the boot 42 can include a structure(e.g., an inwardly projecting flange or lip) that provides a mechanicalinterlock with the recessed portion 128 of the tabs 58. Although thetabs 58 are spaced from the boot 42 by the sealing tube 106, the sealingtube 106 fits tightly around the tabs 58, such that the recessed portion128 of the tabs 58 can be engaged by the boot 42. The sealing member 49is then mounted with the groove 112 about the connector housing 39 tocomplete the installation of connector 32 onto fiber optic cable 20. Theboot 42 retains the coupling nut 40 on the connector housing 39.

Referring to FIGS. 1, 2, 5 and 12, the adapter 34 of the fiber opticconnection system 30 includes an outer housing 44 having a first housingpiece 45 that interconnects with a second housing piece 47. The firsthousing piece 45 defines a first end 70 of the outer housing 44 at whichthe first port 35 is located. The second housing piece 47 defines asecond end 72 of the outer housing 44 at which the second port 37 islocated. An adapter assembly 140 mounts within the outer housing 44. Theadapter 34 also includes a mounting ring or nut 46 that mounts aroundthe exterior of the outer housing 44.

The first housing piece 45 of the adapter 34 includes a first region 60separated from a second region 62 by a shoulder 64. The first and secondregions 60, 62 have generally cylindrical outer shapes and the shoulder64 provides a diameter reduction from the first region 60 to the secondregion 62. The second region 62 defines external threads 66 locatedadjacent the shoulder 64. The external threads 66 are sized to mate withcorresponding internal threads 68 of the mounting nut 46 such that themounting nut 46 can be threaded on the second region 62 of the firsthousing piece 45. The second region 62 also includes a pair ofoppositely positioned latches 167 for use in securing the first housingpiece 45 to the second housing piece 47. Each of the latches 167includes a flexible cantilever arm 170 having a base end integrallyformed with the second region 62. Each cantilever arm 170 defines anopening 172 adapted to receive a corresponding retention tab 174 of thesecond housing piece 47 when the first and second housing pieces 45, 47are connected together.

Referring to FIG. 12, the first region 60 defines the first port 35 ofthe adapter 34. Internal threads 76 are provided within the first region60 adjacent the first end 70 of the housing 44. The internal threads 76within the first port 35 are sized to threadingly receive the exteriorscrew threads 75 of the coupling nut 40 when the coupling nut isthreaded into the first port 35 to provide a secure connection betweenthe first connector 32 and the adapter 34.

Referring now to FIGS. 17 and 19, the first housing piece 45 defines anannular sealing surface 78 positioned inside the first housing piece 45at a location adjacent to the internal threads 76. An angled diametertransition 79 decreases the internal diameter of the first port 35 fromthe internal threads 76 to the annular sealing surface 78. The annularsealing surface 78 is preferably generally cylindrical and is adapted toengage the sealing member 49 of the first connector 32 when the firstconnector 32 is fully inserted within the first port 35. The interfacebetween the annular sealing surface 78 and the sealing member 49provides an internal environmental seal between the first connector 32and the adapter 34.

Referring still to FIGS. 17 and 19, the first housing piece 45 definesan internal pocket 80 within the second region 62 for receiving an endportion of the second housing piece 47 when the housing pieces 45, 47are interconnected. The pocket 80 is separated from the annular sealingsurface 78 by a shoulder 84 that provides an increase in diameter fromthe annular sealing surface 78 to the pocket 80. As shown at FIG. 13, akeying member 150 (e.g., a tab or a rail) is provided at the pocket 80for ensuring proper rotational alignment between the first housing piece45 and the second housing piece 47. The keying member 150 is receivedwithin a corresponding keyway 151 defined by the second housing piece 47when the first and second housing pieces 45, 47 are interconnectedtogether.

The second housing piece 47 of the adapter 34 includes a first region 86separated from a second region 88 by a shoulder 89. The first and secondregions 86 and 88 each have generally cylindrical outer shapes. Theshoulder 89 provides a reduction in outer diameter from the first region86 to the second region 88. The retention tabs 174 for interconnectingthe first housing piece 45 with the second housing piece 47 are providedat the second region 88.

The first region 86 of the second housing piece 47 includes a pair ofoppositely positioned latches 160 for securing the adapter assembly 140within the second housing piece 47. As shown at FIGS. 12 and 17, each ofthe latches 160 includes a flexible cantilever arm 161 having a base end162 integrally formed with the second housing piece 47, and a free end163 positioned opposite from the base end 162. Retention tabs 164 areprovided at the free ends 163. The retention tabs 164 include angledsurfaces 166 that angle toward the central axis of the adapter 34, andretention surfaces 168 that are generally transversely aligned relativeto the central axis of the adapter 34. The first region 86 of the secondhousing piece 47 can also include a keying slot 169 (see FIG. 3) forreceiving a corresponding rail 165 of the second connector 33 to ensurethat the second connector 33 is inserted into the second port 37 at theproper rotational orientation.

The second region 88 of the second housing piece 47 defines the firstplug receptacle 59 for receiving the plug portion 56 of the firstconnector 32 when the first connector is inserted into the first adapterport 35. As previously described, the first plug receptacle 59 has atapered portion defined by opposite surfaces 67, 69 that convergetowards one another as the surfaces extend toward the second end 72 ofthe adapter 34. The tapered configuration of the first plug receptacle59 and the plug portion 56 of the first connector 32 facilitatesmaintaining precise alignment of the first connector 32 within theadapter 34. The first region 86 of the second housing piece 47 alsodefines a second plug receptacle 97 corresponding to the second adapterport 37. The second plug receptacle 97 is adapted for receiving thesecond connector 33.

The adapter assembly 140 of the adapter 34 includes a connectorretention clip 201, a split sleeve 202, and a backing piece 204. Thesplit sleeve 202 is adapted for receiving the ferrules of the first andsecond connectors 32, 33 when the connectors are inserted into theadapter 34 to maintain alignment between the fibers 222 of theconnectors 32, 33. The connector retention clip 201 includes a pair oflatching arms 206 that interlock with the second connector 33 when thesecond connector is inserted within the second port 37 of the adapter34. In this manner, the latching arms 206 retain second connector 33within the second port 37. The connector retention clip 201 alsoincludes a cylindrical receptacle 208 for receiving one end of the splitsleeve 202. The other end of the split sleeve is received within acylindrical receptacle 209 of the backing piece 204. In this manner, thesplit sleeve 202 is captured between the retention clip 201 and thebacking piece 204. Flanges 211, 212 of the retention clip 201 and thebacking piece 204 are secured together to retain the split sleeve 202between the retention clip 201 and the backing piece 204. When the splitsleeve 202 is mounted between the retention clip 201 and the backingpiece 204, the split sleeve 202 has a limited amount of space availablefor sliding axially within the cylindrical receptacles 208, 209.However, this limited space does allow for the split sleeve 202 to floatwithin the cylindrical receptacles 208, 209 in order to provide properalignment between the ferrules 100 of the connectors 32, 33.

The assembled adapter assembly 140 is loaded into the second housingpiece 47 by inserting the adapter assembly 140 into the second plugreceptacle 97 through the second adapter port 37. As the adapterassembly 140 is inserted into the second plug receptacle 97, the flanges211, 212 of the adapter assembly engage the angled surfaces 166 of thecantilever arms 161 causing the cantilever arms to flex outwardly. Afterthe flanges 211, 212 have been pressed past the angled surfaces 166, thecantilever arms 161 snap radially inwardly and retention surfaces 168 ofthe retention tabs 164 capture and retain the adapter assembly 140within the second housing piece 47 (see FIG. 17). As so positioned, theretention clip end of the adapter assembly 140 is accessible from thesecond port 37 of the adapter 34 and the backing piece end of theadapter assembly 140 is accessible from the first port 35 of the adapter34. The flanges 211, 212 are captured between the retention surfaces 168of the retention tabs 164 and a shoulder 213 of the second housing piece47. The cylindrical receptacle 208 of the retention clip 201 ispositioned within the second plug receptacle 97 and the cylindricalreceptacle 209 of the backing piece 204 is located within the first plugreceptacle 59. The split sleeve 202 is aligned generally along thecentral axis of the adapter 34. In the depicted embodiment, the adapterdoes not include structure (e.g., a spring or other biasing or resilientstructure) for facilitating allowing the adapter assembly 140 to floatwithin the outer housing 44. Instead, the retention tabs 164 prevent theadapter assembly 140 from floating or otherwise moving within the outerhousing 44. However, as indicated above, there is a limited amount ofspace between the split sleeve 202, which is disposed within the adapterassembly 140, and the cylindrical receptacles 208,209 that allows forthe split sleeve to float within the cylindrical receptacles 208,209.

After the adapter assembly 140 has been snapped within the secondhousing piece 47 of the outer housing 44, the first and second housingpieces 45, 47 are connected together. For example, the second region 88of the second housing piece 47 is inserted into the pocket 80 definedwithin the second region 62 of the first housing piece 45. Duringinsertion, rotational alignment is ensured by inserting the keyingmember 150 of the first housing piece 45 into the keyway 151 of thesecond housing piece 47. As the second housing piece 47 is inserted intothe first housing piece 45, the cantilever arms 170 engage the retentiontabs 174 causing the cantilever arms 170 to flex radially outwardly.When the openings 172 of the cantilever arms 170 align with theretention tabs 174, the cantilever arms snap radially inwardly to alocked position in which the retention tabs 174 protrude through theopenings 172.

The adapter 34 is adapted to be mounted within an opening defined by awall of the enclosure 19. To mount the adapter 34 in the opening, themounting nut 46 is first removed. The second end of the outer housing 44is then inserted from the exterior of the enclosure through the mountingopening until the shoulder 64 abuts against the outside surface of theenclosure wall. Thereafter, the mounting nut 46 is threaded on thethreads 66 until the nut abuts against the inside surface of theenclosure wall. With the enclosure wall captured between the shoulder 64and the mounting nut 46, the adapter 34 is securely mounted to theenclosure.

As indicated above, the adapter 34 is configured for providing anoptical connection between the first connector 32 and the secondconnector 33. To provide this connection, the first connector 32 ismounted in the first port 35 and the second connector 33 is mounted inthe second adapter port 37. To mount the first connector 32 in the firstadapter port 35, the first connector 32 is inserted axially into theport 35 until the plug portion 56 fits within the first plug receptacle59 and the latch 50 snaps within the notch 82. As so positioned, theferrule 100 fits within one end of the split sleeve 202 and the sealingmember 49 engages the annular sealing surface 78. The connection isfinalized by threading the coupling nut 40 into the internal threads 76of the adapter 34 until an end surface 115 (shown in FIGS. 7 and 17) ofthe coupling nut 40 abuts the circumferential shoulder 113 of theconnector housing 39, thereby retaining the connector housing 39 againstthe second region 88 of the second housing piece 47 of the adapter 34(as shown in FIG. 17). The second connector 33 is mounted in the secondadapter port 37 by inserting the connector axially into the port 37until the connector 33 is snapped between the arms 206 of the connectorretention clip 201. As so positioned, a ferrule 230 of the connector 33is received within the other end of the split sleeve 202 such that theferrules 230, 100 are held in axial alignment with one another.

The fiber optic connection system 30 preferably has a compactconfiguration adapted to provide relatively high circuit densities. Inone embodiment, the diameter D1 of the sealing member 49 (see FIG. 7)and the diameter D2 of the annular sealing surface 78 (see FIG. 17) eachare less than or equal to 15 mm. In an alternate embodiment, thediameter D1 of the sealing member 49 and the diameter D2 of the annularsealing surface 78 each are less than or equal to 12.5 mm. In anotherembodiment, the diameter D1 of the sealing member 49 and the diameter D2of the annular sealing surface 78 each are less than 10 mm.

FIGS. 20-23 depict another fiber optic connection system 330 havingfeatures that are examples of inventive aspects in accordance with theprinciples of the present disclosure. The system includes a firstconnector 332 and an adapter 334 for optically connecting the firstconnector 332 to another connector. The structure of the fiber opticconnection system has the same general configuration as the system 30 ofFIGS. 1-22 except that the connector 332 includes multi-terminationferrule 301 (e.g., a ferrule with more that one fiber mounted therein)and the adapter 334 is adapter for connecting a first multi-terminationconnector to a second multi-termination connector. The multi-terminationferrule 301 has a generally rectangular configuration, and the adapter334 includes generally rectangular multi-termination ferrule receptaclesfor accommodating multi-termination ferrules.

From the forgoing detailed description, it will be evident thatmodifications and variations can be made in the devices of thedisclosure without departing from the spirit or scope of the invention.

What is claimed is:
 1. A fiber optic connector for optically coupling toa mating fiber optic connector through a fiber optic adapter, the fiberoptic connector comprising: a connector housing extending from a distalend to a proximal end; a ferrule assembly mounted to the connectorhousing adjacent the proximal end, the ferrule assembly including aferrule, a distal end of the ferrule extending distally beyond thedistal end of the connector housing; a sealing member mounted directlyaround an exterior of the connector housing and adapted for providing aseal between the connector housing and the fiber optic adapter when thefiber optic connector is plugged into a port of the fiber optic adapter,the sealing member having a diameter less than or equal to 15millimeters; and a fastener configured to retain the fiber opticconnector within the fiber optic adapter.
 2. The fiber optic connectorof claim 1, wherein the fastener is configured to be turned relative tothe connector housing to engage or disengage the fiber optic adapter. 3.The fiber optic connector of claim 1, wherein the fastener includes aninterlocking feature configured to mate with a corresponding feature ofthe fiber optic adapter.
 4. The fiber optic connector of claim 1,further comprising a strain relief boot mounted adjacent the proximateend of the connector housing.
 5. The fiber optic connector of claim 1,wherein the diameter of the sealing member is less than or equal to 12.5millimeters.
 6. The fiber optic connector of claim 1, wherein thediameter of the sealing member is less than 10 millimeters.
 7. The fiberoptic connector of claim 1, wherein the exterior of the connectorhousing includes a circumferential groove for mounting the sealingmember.
 8. The fiber optic connector of claim 1, wherein the sealingmember is an O-ring seal.
 9. The fiber optic connector of claim 1,wherein the mating fiber optic connector is a conventional SC connector.10. The fiber optic connector of claim 1, wherein the ferrule assemblyfurther includes a barrel mounted on the ferrule, a spring and a springholder.
 11. The fiber optic connector of claim 1, wherein the fiberoptic adapter includes an outer housing and wherein an adapter assemblymounts within the outer housing.
 12. The fiber optic connector of claim11, wherein the fiber optic adapter includes a mounting nut that mountson an exterior of the outer housing.
 13. The fiber optic connector ofclaim 11, wherein the fiber optic adapter does not include structure forallowing the adapter assembly to float within the outer housing.
 14. Thefiber optic connector of claim 11, wherein the outer housing includes apair of oppositely positioned latches for securing the adapter assemblywithin the outer housing, wherein the latches include retention tabs,and wherein the retention tabs prevent the adapter assembly fromfloating or otherwise moving within the outer housing.
 15. The fiberoptic connector of claim 11, wherein the adapter assembly includes aconnector retention clip, a split sleeve and a backing piece, whereinthe split sleeve is adapted for receiving the ferrule of the fiber opticconnector and a ferrule of the mating fiber optic connector when thefiber optic connector and the mating fiber optic connector are insertedinto the fiber optic adapter to maintain alignment between fibers of thefiber optic connector and the mating fiber optic connector, wherein theconnector retention clip includes a pair of latching arms that interlockwith the mating fiber optic connector when the mating fiber opticconnector is inserted within the fiber optic adapter, wherein theconnector retention clip includes a cylindrical receptacle for receivingone end of the split sleeve, and wherein the other end of the splitsleeve is received within a cylindrical receptacle of the backing piece.16. The fiber optic connector of claim 15, wherein the fiber opticadapter does not include structure for allowing the adapter assembly tofloat within the outer housing.
 17. The fiber optic connector of claim15, wherein the outer housing includes a pair of oppositely positionedlatches for securing the adapter assembly within the outer housing,wherein the latches include retention tabs, and wherein the retentiontabs prevent the adapter assembly from floating or otherwise movingwithin the outer housing.
 18. A fiber optic connector for opticallycoupling to a mating fiber optic connector through a fiber opticadapter, the fiber optic connector comprising: a connector housingextending from a distal end to a proximal end; a ferrule assemblymounted to the connector housing adjacent the proximal end, the ferruleassembly including a ferrule, a distal end of the ferrule extendingdistally beyond the distal end of the connector housing; a sealingmember mounted directly around an exterior of the connector housing andadapted for providing a seal between the connector housing and the fiberoptic adapter when the fiber optic connector is plugged into a port ofthe fiber optic adapter, the sealing member having a diameter less thanor equal to 15 millimeters; and a twist-to-lock fastener configured toretain the fiber optic connector within the fiber optic adapter, thefiber optic adapter including an outer housing, wherein an adapterassembly mounts within the outer housing.
 19. The fiber optic connectorof claim 18, wherein the fiber optic adapter includes a mounting nutthat mounts on an exterior of the outer housing.
 20. The fiber opticconnector of claim 18, wherein the fiber optic adapter does not includestructure for allowing the adapter assembly to float within the outerhousing.
 21. A fiber optic connection system for optically connecting afirst fiber optic cable to a second fiber optic cable, the fiber opticconnection system comprising: a fiber optic adapter; a first fiber opticconnector terminating the second fiber optic cable; and a second fiberoptic connector terminating the second fiber optic cable; the fiberoptic adapter including a first port for receiving the first fiber opticconnector and a second port for receiving the second fiber opticconnector, the first fiber optic cable being optically coupled to thesecond fiber optic cable when the first and second fiber opticconnectors are positioned within their respective first and second portsof the fiber optic adapter; the first fiber optic connector including: aconnector housing that extends from a distal end to a proximal end; aferrule assembly mounted adjacent to the distal end of the connectorhousing and having a ferrule that projects beyond the distal end of theconnector housing; and a sealing member that mounts around an exteriorof the connector housing, the sealing member being adapted for providinga seal between the connector housing and the fiber optic adapter whenthe first fiber optic connector is plugged into the first port of thefiber optic adapter, the seal being located within the first port of thefiber optic adapter, and the sealing member of the first fiber opticconnector having a diameter D1 less than or equal to 12.5 millimeters.22. The fiber optic connection system of claim 21, wherein the firstfiber optic connector includes a fastening structure for retaining thefirst fiber optic connector within the first port of the fiber opticadapter, and wherein the fastening structure is turned to engage anddisengage the fiber optic adapter.
 23. The fiber optic connection systemof claim 21, wherein the exterior of the connector housing includes acircumferential groove for mounting the sealing member.
 24. The fiberoptic connection system of claim 21, wherein the fiber optic adapterincludes an outer housing and wherein an adapter assembly mounts withinthe outer housing.
 25. The fiber optic connection system of claim 24,wherein the fiber optic adapter includes a mounting nut that mounts onan exterior of the outer housing.